B1271

DTC B1271

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.



DTC Descriptor
DTC B1271
- Theft Locked




Circuit/System Description

This DTC is generated by the module when the theft lock is activated. This occurs when the VIN as received over the communication circuit and the VIN as stored in the module memory do not match. This also occurs when no VIN is received over the communication circuit.


Conditions for Running the DTC

This test is run every 300 milliseconds.


Conditions for Setting the DTC

This DTC is generated by the module when the VIN as received over the communication circuit and the VIN as stored in the module memory do not match. This also occurs if no VIN is received over the communication circuit. This DTC test runs when the radio changes from OFF to ON.


Action Taken When the DTC Sets

The radio does not function. The radio will display Locked - THEFTLOCK Active.


Conditions for Clearing the DTC

Re-calibration with the correct calibrations for the vehicle and cycling the radio to OFF then to ON will clear the DTC if there is no damage to the radio.


Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information


Circuit/System Testing

Ignition ON the ignition, with the engine OFF. With a scan tool, clear the radio theft information and DTC. Cycle the ignition and verify the DTC did not reset.

If the DTC resets, replace the radio.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning)for radio replacement, setup, and programming